Vaccinations. They’re considered to be one of the biggest, most important medical advancements ever made against the spread of infectious disease. They save lives and prevent so much suffering. But what do you really know about vaccines?

How vaccines work:
A baby’s immune system starts working long before birth. While in the womb, the mother’s antibodies protect baby from illness, making the womb a safe place.

Once a baby is born, it has a totally naïve and inexperienced immune system, yet their immune response is truly amazing. Their little bodies can respond to any virus or bacteria and create an immune response quickly and effectively (for the most part). Also, babies who are breastfed get even more antibodies and protection from their mothers’ milk. But all of this isn’t enough, which is why we start vaccinating babies at birth.

Babies receive a hepatitis B vaccine right after they’re born. Then at 2 months, they receive D-TAP (diphtheria, tetanus and pertussis), HIB (haemophilus influenzae type B), pneumococcal and rotavirus vaccines. These illnesses are serious diseases for someone of any age, but particularly for infants. For example, pertussis, also known as whooping cough, can put a baby in the hospital for months, or even cause death.

For a schedule of infant and child vaccines (through age 6), have a look at this easy-to-read form.

What is Herd Immunity?
Herd immunity is the concept that you and your neighbor are protected against disease when 90-95% of the “herd” (population) is immunized. When that large percentage of people is immune to an illness, it’s nearly impossible for a widespread epidemic to occur.

Think about it this way: Consider germs to be rain. Immunization is a raincoat. You still may get wet with a raincoat, so you need an umbrella, so the umbrella is herd immunity.

Newborns and infants don’t have raincoats because they’re so new. They rely on the “umbrellas” for protection, which is the rest of us being immune through vaccination.

For the remainder of this blog, I’d like to answer some of the most common questions about vaccines.

1. It seems like the vaccines are a lot of scary stuff we put into babies. Are there risks to taking a delayed schedule?

Yes, there are risks. I, too, have heard the concerns from parents about too many shots too soon, and I’ve actually done a lot of research and found that many doctors, scientists and researchers have worked together on the recommended vaccination schedule.

The goal is to protect babies as safely and as quickly as possible. Babies’ immune systems are miraculous. They can mount an amazing response to challenges, and actually, our current vaccination loads are much less than were given 20 years ago. While it may seem like they’re getting a lot of shots, they’re receiving fewer total challenges. By delaying shots, you’re leaving your child unprotected when they’re most vulnerable.

Here’s additional information on this topic compiled from both the CDC (Centers for Disease Control) and the World Health Organization.

An infant’s immune system is more than ready to respond to the very small number of weakened and killed infectious agents (antigens) in vaccines. From the moment babies are born, they are exposed to numerous bacteria and viruses on a daily basis. Eating food introduces new bacteria into the body; numerous bacteria live in the mouth and nose. An infant places his or her hands or other objects in his or her mouth hundreds of times every hour, exposing the immune system to still more antigens. A child is exposed to far more antigens from a common cold or sore throat than they are from vaccines.

When you are in the womb, you are in a sterile environment. When you enter the birth canal and the world, you are not, and very quickly there are trillions of bacteria on the surface of your body. You have about 100,000 trillion bacteria on the surface of your body… more bacteria is on the surface of your body than the number of cells you have in your body.

One single bacteria has between 2000 and 6000 immunologic components. If you add up all of the immunologic components in vaccines that are given in the first few years of life, it comes to only about 160. Taking a cotton swab of the inside of the child's nose and viewing it on a microscope slide reveals that it’s teeming with bacteria which is much higher than what a baby receives in any vaccine.

I want to also make clear that I recognize when parents are having questions about vaccines, that they’re truly wanting to make the best decision for their child. I respect that they’re scared and have questions. So please, please, please talk with your doctor about your concerns, so that you can be partners in caring for your child.

2. What about an increased risk of autism? I've seen so many stories about vaccines possibly triggering or causing autism.

First, let’s talk about what autism is. It is a blanket term for a collection of disorders that have three factors in common:

Abnormal social skills

Abnormal communication skills

Repetitive or obsessive traits

There is a huge range—also called a spectrum—of ability and disability. Some clues would be not meeting developmental milestones--poor eye contact and engagement in infancy, such as not connecting with parents by age 1. Children with autism have autism before their first birthday, even though they have not been formally diagnosed. It’s true that we don’t know what causes autism. The three big areas of interest right now are genetic causes, abnormal brain growth, and other environmental triggers. Since all the controversy, researchers have taken a long, extensive look at vaccines and their possible connection to autism. There is absolutely no conclusive evidence that vaccine exposure triggers or causes autism. As I’ve mentioned, there are several theories being explored right now. What they all seem to have in common is that they’re focusing on what happens prior to a child’s term birth, particularly prematurity, maternal viral infections during pregnancy, older parents and closely-spaced pregnancies. None of these have been identified as causes, but their correlation is being explored as possible clues to the origin of autism.

3. I have a lot of "crunchy" friends who don't understand herd immunity and vaccine effectiveness (they often claim that the fact that vaccines aren't 100% effective is reason enough not to administer them). They seem to rely on herd immunity to keep them and their children safe. Please explain.

No medical treatment is 100% effective in 100% of people 100% of the time. However, a vaccine NOT given is 100% not effective.

There are measles outbreaks right now in the US, in areas of the country where immunization rates have dropped below the 90% herd immunity rate. Yet in areas where the vaccination rates are high, there are not measles outbreaks.

That’s how immunizations and herd immunity works. If more than 90% of people have been immunized, outbreaks are far less likely to occur. Because we have become such a global community, anyone can travel from anywhere. And because most illnesses are contagious prior to symptoms, we have no idea what we’re being exposed to.

4. Why are babies often given the same amount of a vaccine as a 300 lb adult?

It really depends on the type of vaccine. For example, the DTaP is for children six and under because it contains more vaccine for diphtheria which is of greater risk in this age group. However, people 7 and older receive a Tdap. This vaccine is heavier on tetanus, but lower on the other components.
Same goes for the flu shot. Children ages 6-36 months get a split, preservative-free vaccine in two doses, whereas healthy adults get a single larger dose. We give even higher doses to people age 65+, because their immune systems require more virus particles to mount an immune response.

Another example, the MMR, is a standard size, but is typically only given at ages 1 and 5. Most people aren’t receiving this vaccine at older ages.